When the novel first came out as a book, Thackeray drew a bunch of illustrations to go with it. They were so bad and so universally made fun of that he took them out of every edition that followed. Just look at the faces to see the horrendousness.
Thackeray drew a lot of funny pictures of himself. Here is one.
While Thackeray was writing this novel, his wife was becoming more and more mentally ill. By the time he finished, she had to be institutionalized and had lost pretty much all touch with reality. Many times when he visited her, she would not recognize him. His diary and letters describe all of this in sad, graphic detail.
One of his daughters, Anne Thackeray Ritchie, grew up to be a reasonably famous writer herself.
Thackeray died very suddenly at a fairly young age – 47 – from some kind of gastrointestinal problems. Here is an 1864 obituary from the New York Times.